Don't set shell to /bin/sh on Windows. Setting the shell to sh on Windows breaks eg. Vundle.

Signed-off-by: ljani <ljani@server.fake>
Added smart case to the ack command for those using ag.
Merge pull request #393 from teasp00n/3.0

Added smart case to the ack command for those using ag.
Merge pull request #391 from ljani/3.0

Don't set shell to /bin/sh on Windows
Default to utf-8 internally on Windows and use cp850 for terminal. Also set some default fileencoding heuristics that are likely to match not only Windows files but also standard encodings of the 2010s. This fixes at least two problems on Windows: 1. The Windows installer currently throws errors, because Python(?) doesn't work properly without proper encoding. 2. Ticket #340, which had problems with utf-8 listchars working properly unless they were re-set in .vimrc.local with the correct encoding.

Signed-off-by: ljani <ljani@fake.server>
Merge pull request #394 from ljani/fix-windows-encodings

Set default encodings on Windows
Merge remote-tracking branch 'origin' into 3.0